The present invention relates generally to non-fat and reduced-fat products which possess the organoleptic characteristics of full fat-containing products and more particularly to frozen dessert products such as ice cream and related frozen dairy desserts. Additionally, the present invention relates to a cream substitute ingredient formed of coagulable protein such as egg white enveloping a nucleating agent such as casein micelles and to novel food products including frozen desserts, mousses, cream pie fillings and icings, which contain this cream substitute.
"Frozen dessert" is a generic term applied to a wide variety of products including ice cream, frozen custard, ice milk, sherbet, water ice, frozen dairy confections, frozen confections, dietary frozen desserts, Mellorine and non-dairy desserts, all of which are defined according to U.S. Government Federal Standards of identity. Frozen dessert products for which no Federal Standards exist include frozen puddings, mousse and frozen shakes. Among the "dairy" frozen desserts minimum standards exist for milk fat and/or milk solids content. For example, ice cream must contain not less than 10% milk fat and 20% total milk solids (comprised of the total of milk fat and Milk Solids Non-Fat, "MSNF"); ice milk must contain 2 to 7% milk fat and not less than 11% total milk solids; and sherbet must contain 1 to 2% milk fat and 2 to 5% total milk solids. See, generally, Redfern, R. S. and Arbuckle, W. S., "Ice Cream Technology Manual", 4th Ed., 1985, Redfern & Assoc. Ltd., Raleigh, N.C. 27622, the disclosures of which are incorporated by reference herein for purposes of establishing the background of the invention.
Ice creams and other whipped frozen dairy desserts are actually rather complicated forms consisting of air bubbles surrounded by a partly frozen emulsion wherein ice crystals and solidified fat globules are embedded in the unfrozen water phase. Estimates of the sizes of the coarsely dispersed structural components of ice cream vary. Ice crystal sizes are reported to vary in size between 20 to 60 microns in diameter and to be situated approximately 7 microns apart; air cells are reported to range in size between 10 to 175 microns and to be situated about 125 microns apart; and solidified fat globules are reported to vary in size from 0.2 to 2.0 microns and to form agglomerations providing a "skin" around trapped air cells. See, B. H., et al., eds., Avi Publishing Company, Inc., Westport, Conn., at pages 896-14 913, the disclosures of which are incorporated by reference herein for purposes of establishing the background of the invention.
It is well known that the fat content of frozen dairy desserts plays a substantial role not only in the body and texture of the product, but also its flavor characteristics. Smoothness of ice cream texture is essentially inversely proportional to the average size of ice crystals. Increases in the milk fat content for virtually any given frozen dessert formulation will both decrease the ice crystal size and the distance between crystals. Despite the expense and high caloric value attending use of milk fat, as well as the susceptibility of milk fat to oxidation causing off flavors and its propensity to provide whipped or buttery texture effects, full fat ice cream products are generally more widely preferred to ice milk, sherbets and the like. Indeed, the so-called "premium grade" ice creams are essentially characterized by higher than standard milk fat contents in the range of 15 to 18% and are recognized as products of correspondingly increased palatability and smoothness and enhanced body and texture in comparison to standard grade ice cream and dairy dessert products having lower fat contents.
While attempts have been made to develop frozen dessert product formulations wherein part or all of the milk fat content ordinarily present is replaced by a non-fat material, none of the resulting products has achieved any substantial success as a replacement for full fat ice cream or ice milk. See, for example, U.S. Letters Patent No. 4,510,166 relating to ice cream formulations wherein starch gels are suggested as fat replacement materials and U.S. Letters Patent Nos. 4,421,778 and 4,552,773 relating to whipped food products incorporating beta-phase tending crystalline fats. See also, British Patent No. 915,389 and U.S. Letters Patent Nos. 3,510,316, 3,556,813, 4,400,405, and 4,631,196.
There thus continues to exist a long standing need in the art for non-fat and reduced fat frozen dessert products which possess the physical and organoleptic characteristics of full fat frozen dairy desserts. Ideally, such products would equal or surpass standard frozen whipped dessert products in nutritional value but have reduced caloric content. Additionally, there exists a need for a fat or cream substitute ingredient that can be prepared, stored and used in making a variety of low/no fat food products including frozen whipped desserts.